An embodiment of the present invention relates to a system for supplying LNG fuel.
A ship is a transport vehicle for sailing across the ocean, carrying bulk of minerals, crude oil, natural gas, several thousands of containers, etc. A ship is made of steel and moves by propulsion generated through the rotation of a propeller when it is floating on a water plane by buoyancy.
A ship generates propulsion by driving an engine. The engine moves a piston using a gasoline or diesel and rotates a crankshaft by a reciprocating motion performed by the piston, so that a shaft connected to the crankshaft rotates to drive the propeller.
However, recently, a Liquefied Natural Gas (LNG) carrier is using LNG fuel supplying method of driving an engine using LNG as a fuel. This LNG fuel supplying method has also been used in other ships in addition to the LNG carrier.
It is generally known that LNG is clean fuel and LNG deposits are greater than oil reserves. LNG consumption has surged with development of a mining technique and a transporting technique. Methane, which is the main component of LNG, is generally kept in a liquid state at a temperature of −162° C. or less under 1 atmospheric pressure. The volume of the liquefied methane is approximately 1/600 of that of methane in a gaseous state as the standard state, and the specific gravity of the liquefied methane is 0.42, which is about half of the specific gravity of the crude oil.
However, the temperature and the pressure, etc. for driving the engine may be different from the state of LNG stored in a tank. Accordingly, research and development of a technique for supplying LNG to an engine by controlling the temperature and the pressure, etc. of the stored LNG in a liquid state has continued.